中文摘要：

土霉素（OTC）和Zn^2＋作为饲料添加剂大量应用于畜禽养殖中,会通过畜禽粪便施用等方式进入土壤环境.研究了它们在粘土矿物上的吸附行为及其相互影响.结果发现,阳离子交换量大的蒙脱石对OTC的吸附系数（Kd）明显高于高岭石;而电荷属性的不同,导致2种粘土的Kd随pH呈现不同的趋势.Zn2＋可对OTC吸附产生影响,在4%@ 0250-3301

英文摘要：

Oxytetracycline （OTC） and Zn^2＋ are both widely used as growth promoters in concentrated animal feeding operations, which are discharged into soil system by manure application. There is special environment significance to study the sorption and interaction of OTC with accompanied metal cations on clays to elucidate their environmental behaviors and to assess ecological risks. Much stronger sorption of OTC was observed on montmoriUonite than that on kaolinite, which might be resulted from the larger cation exchange capacity of the former. Different pH-dependent Kd patterns were illustrated on montmorillonite and kaolinite, which might be contributed by the different properties of surface charge. During 4 〈 pH 〈 5, OTC sorption was decreased by cation competition of Zn^2＋, while OTC sorption was promoted by OTC-Zn-clay bridge while 5 〈 pH 〈 9, and the most significant effect was shown at pH = 6.5. The sorption of Zn^2＋ on two clays was decreased by OTC in the pH range studied, which can be explained by cation competition of OTC at lower pH, or by prohibition in the sorption or precipitation resulted from complexation between OTC and Zn^2＋ at higher pH. CD and UV-Vis spectrometry analysis showed that there was no complexation observed between OTC and Zn^2＋ at pH = 4. But with increasing of pH value, complexation might happen at the sites of O11, O12 or O12, O1.